Hazard-prevention system for a vehicle

ABSTRACT

The invention relates to a hazard-prevention system for a vehicle. The vehicle has devices for sensing driving state variables, for sensing ambient data and for sensing the driver&#39;s activity, and a data processing device. The data processing device is provided for processing the sensed data and for actuating a safety device in accordance with a predefined control strategy. According to the invention, the vehicle has a device for identifying the driver, and the data processing device derives a driver load factor related specifically to the driver from the driving state variables, the ambient data and the data relating to the activity of the driver, and said driver load factor is used to adapt the control strategy.

[0001] The invention relates to a hazard-prevention system for a vehicleaccording to the preamble of patent claim 1.

[0002] Contemporary systems for increasing safety and comfort for theoccupants of a motor vehicle use a number of devices for sensinginformation. In particular, driving state variables, ambient data and,to an increasing degree, information relating to the vehicle occupantsand the driver of the vehicle are sensed.

[0003] The driving state variables are understood to be variables suchas speed, yaw acceleration, longitudinal acceleration and transverseacceleration, brake pedal setting and accelerator pedal setting,steering angle, the status of operator control elements such as flashingindicator lights and hazard warning lights and the status of sensors andcontrol devices.

[0004] Data which is made available by ambient sensors, telematicsystems and by the vehicle communicating with other vehicles and fixedcommunication systems is referred to as ambient data. Examples ofambient data is information on the current location (for example whetherthe route being travelled on is in a residential area, at the edge of awood or on a bridge), on the category of road (for example whether theroad being travelled on is a motorway, a secondary road, a single-laneroad, multilane road with or without oncoming traffic), and on the laneon which the actual vehicle is travelling. Further ambient data is thestate of the road, temperature, weather conditions, light conditions,ambient noise, air quality and wind conditions, speed, distance,directional movement, type and state of the vehicles travelling ahead,adjacent vehicles, vehicles travelling behind or oncoming vehicles andof other road users.

[0005] Information on the vehicle occupants and the driver are, forexample the occupation of the seats, the weight of the vehicleoccupants, the size of the vehicle occupants and in particular theposition of the vehicle occupants. Sensing the driver's activity alsocomprises, for example detecting the eye movements, the viewingdirection but also the operator control processes of operator controlelements such as, for example, the radio, steering wheel, the gearselector lever, brake pedal, mirror adjustment device, air-conditioningsystem, seat adjustment device, speech-operated control device,navigation module and mobile telephone.

[0006] From such information it is possible to infer that the vehicleoccupants are being put at risk or other road users are being put atrisk. Systems for evaluating this information in order to reduce a riskfor the occupants of motor vehicles are known.

[0007] The generic-type-forming DE 43 38 244 C2 discloses ahazard-prevention system which has a driving state monitoring system, asurroundings monitoring system, a driver monitoring system and a devicefor carrying out a hazard-prevention operation. A hazard situation isdetermined from the data relating to the movement state and operatingstate and the ambient data, and the hazard potential of said situationis evaluated. If the vehicle is in a hazardous situation, a decision ismade on the basis of the data relating to the state and action of thedriver as to whether the driver has perceived the hazardous situation. Ahazard-prevention process is carried out only if the driver has notperceived the hazardous situation. In order to prevent the hazard, avisual or audible signal is output or an intervention into thevehicle-movement dynamics of the vehicle is made.

[0008] In relation to perceiving the hazardous situation, the driver isalso provided with other information, for example route information,radio information or vocal information. The ability to simultaneouslyperceive a plurality of information items and rapidly process theperceived information is developed to different degrees in people. Owingto a varying information density during a journey, the driver is subjectto different load factors depending on the situation. Every driver hasan individual, different load factor which he can cope with, and thus inassociation with this an individual, different perception capability aswell as individual long-term changes and short-term fluctuations in hisability to cope with the load factor and perception capability.Fluctuating abilities to cope with a load factor and varying objectiveload factors can lead to a situation where, given a general warningsystem in which the individual load factor is not taken into account, awarning is issued to the driver too early or too late, and a hazardoussituation is therefore counteracted only to an inadequate degree.

[0009] The object of the invention is to reduce the frequency ofaccidents in motor vehicles and reduce the severity of accidents. Thisobject is achieved according to the invention by means of the featuresof claim 1.

[0010] The hazard-prevention system for a vehicle contains a device forsensing driving state variables, a device for sensing ambient data, adevice for sensing the driver's activity and a data processing device.The data processing device processes the sensed data and actuates asafety device in accordance with a predefined control strategy.According to the invention, the vehicle has a device for identifying thedriver. Furthermore, the data processing device derives a measurerelated specifically to the driver which is characteristic of theinstantaneous load factor of the driver from the driving statevariables, the ambient data and the data relating to the activity of thedriver. The control device adapts the control strategy for actuating thesafety device to the measure of the load factor of the driver. Theadvantage of this hazard-prevention system of a vehicle is that thedriver's safety and comfort are increased and the safety of the vehicleoccupants and of other road users is increased.

[0011] The driver is identified by evaluating vehicle-related variables,that is to say for example data is transferred from the gearboxcontroller or engine controller and is used to describe the type ofdriver (aggressive, nervous, tentative, dynamic). In addition,interventions by the driver in systems for controlling the dynamics ofvehicle movement such as ABS (Anti-lock Brake System) ESP (ElectronicStability Program, Driving Stability System), BBS (Brake BoostingSystem) are sensed and evaluated. Personal features such as the settingof the seat, the setting of the rear mirror, the setting of theair-conditioning system or the preferred radio station can be used toidentify the driver. Alternatively, the identification of the driver iscarried out by means of a person-related use authorization means (forexample key, keyless go card) or by means of eye recognition, speechrecognition, recognition of fingerprints).

[0012] In one development of the hazard-prevention system, the vehiclehas a device for storing the driver-related history which contains datawhich is characteristic of the respective driver. The data processingdevice uses, in addition to the information specified in claim 1, thedriver-related history to derive a measure of the load factor of thedriver. The device for storing the driver-related history senses inparticular the driver's activity and creates a history of the driver'sactivity. The driver-related history can additionally contain ambientdata and driving state variables. It is possible, for example, to assigneach driver a route profile, a speed profile, a specific route which istravelled on regularly and a specific safety distance. In thedriver-related history it is possible to distinguish between a long-termhistory and a short-term history. The short-term history contains thecharacteristic features of the current journey or of another predefinedtime period, for example a day. The long-term driver-related historycontains the characteristic specific features of the driver over apredefined relatively long period of time, for example since the lasttime the owner of the vehicle changed, since an illness or an accidentof the driver, since the last time the tyres were changed or the lastservice or since the driver changed workshop. By evaluating a history itis detected, for example, whether the current journey is a routinejourney which is characterized by an accident risk which is changed.Furthermore, when evaluating a risk it is possible to take into accountany particular strengths, weaknesses and particularities of the driver.These features relate, for example, to the attentiveness (reduced duringroutine journey), perception (relatively uncertain driving style whentravelling at night as opposed to day), reaction capability (longer timeuntil the pedal is activated) or the specific capability, for examplewhen simultaneously controlling a plurality of functions (for exampledriving function, plus navigation, plus mobile radio). An advantage ofthis development of the hazard-prevention system is that thedetermination of the degree of loading on the driver is improved, as aresult of which safety is further increased in road traffic.

[0013] In one embodiment of the hazard-prevention system for a vehicle,the safety device comprises an information and warning system or isformed by an information and warning system. The processing of thesensed data is carried out by the data processing device in such a waythat those action possibilities of the driver which reduce or rule out ahazard are determined and that it is checked whether the driver isbehaving in accordance with the determined action possibilities. Inaddition, it is determined whether the measure of the hazard changesrapidly and whether this measure lies within predefinable limits. If themeasure of the hazard exceeds a predefinable limit, the driver isnormally informed, in a first step and/or warned as a function of theseverity and the profile of the hazard.

[0014] In the following example, the vehicle is travelling with a cruisecontroller with a device for controlling the distance between vehicleson a road with good infrastructure. The driver's activity is sensed andthe reaction capability, the degree of attentiveness etc. are evaluated.A current driver load factor is derived from this driver data which isdetermined and evaluated, from further individual driver data and, forexample, the ambient data. The time of issuing information/a warning tothe driver, for example a transfer request which is issued in predefinedsituations by the cruise control device for controlling distance betweenvehicles is calculated from this driver load factor. If the drivingsituation then changes to the effect that the driver is to be requestedto perform the longitudinal control of the vehicle because the distancefrom an obstacle is reduced below a predefinable safety distance, thedriver will receive a first information item/warning.

[0015] If there is no reaction from the driver after a waiting timewhich is predefined in particular as a function of the driver loadfactor, a second warning will be issued. The warnings can be issued insuch a way that the normal reaction of a driver to these warnings bringsabout an action which counteracts the hazardous situation. Warnings forthe driver which are provided for this purpose may address varioussenses and may be, for example, audible, visual, haptic or olfactory.

[0016] As an alternative to or in addition to information/a warning tothe driver, a warning signal can be transmitted to another road user, inparticular to a non-motorized road user. When there is the risk of acollision with a pedestrian, it is possible to generate a noise or alight signal which is intended to cause the pedestrian to react in a waywhich is suitable to prevent the collision, for example by thepedestrian stopping. The signals can be varied as a function of thehazardous situation, for example a light signal can be changed inintensity, in the flashing frequency, in colour and direction. Inanother situation, an acoustic warning signal, for example the squealingof a tyre can cause a driver of a motor bike to refrain from performingan originally planned change in the direction of travel, avoiding acollision between the vehicle and the rider of the motorbike. Thedescribed warning to other road users (partner warning) is carried outaccording to the invention taking into account the individual driverload factor and the possible actions by the driver and/or those actuallycarried out by the driver.

[0017] It is also possible to issue a warning to others without takinginto account the specific load factor but taking into account thepossible and/or actual actions of the driver. Furthermore, a warning toothers without taking into account the specific driver load factor andwithout taking into account the possible and/or actual actions of thedriver can be carried out in order to reduce the probability of anaccident or the severity of an accident. A warning to others fornon-motorized road users may, for example, sound the horn at apedestrian in order to prevent him stepping onto the carriageway orwalks into the likely path of the vehicle on the carriageway onto whichhe has just stepped.

[0018] In another refinement of the hazard-prevention system for avehicle, the safety device comprises a system for controlling thedynamics of vehicle movement. Here, the safety device can compriseexclusively a system for controlling the dynamics of vehicle movement ora system for controlling the dynamics of vehicle movement in conjunctionwith an information and warning system, or be formed from these systems.If, with or without previous information/warning being issued to thedriver, there is no driver reaction, an inadequate driver reaction or adriver reaction which would increase the hazard, the hazard-preventionsystem intervenes in the vehicle movement dynamics. This may be anintervention in the brake system, for example emergency braking, anintervention in the vehicle steering system, for example an avoidancemanoeuvre or some other intervention into the dynamics of the vehiclemovement. Such an intervention by the hazard-prevention system can becarried out in order to avoid an accident and to reduce the severity ofan accident. Such an intervention is aborted as soon as there issufficient driver reaction or a reduction in the hazard below aprescribed value. An example of a driver reaction which leads to anintervention being aborted is the activation of the brake pedal by thedriver during automatic braking. As a result, the driver assumesresponsibility for the braking operation and the automatic braking isterminated.

[0019] In a further refinement of the hazard-prevention system for avehicle, the safety device comprises a vehicle-occupant protectionsystem which acts on the movement of the vehicle occupant and isintended to make the consequences of an accident less severe. When thereis a predefined hazard, determined taking into account the driver loadfactor, the vehicle occupant protection system which acts on themovement of the vehicle occupant is actuated by the hazard-preventionsystem with or without a preceding information/warning function and/orintervention in the vehicle movement dynamics. Examples of protectionsystems which act on the movement of a vehicle occupant are conventionalrestraint systems such as airbags and seat belt pretensioners and noveldevices for absorbing energy in which the hardness and the deformationbehaviour can be controlled. Means for preconditioning the vehicleoccupants, for example by adapting the setting of the seat system inaccordance with the hazard, or reversible protection systems, such aselectromotive seat belt pretensioners, are also to be understood asvehicle occupant protection systems which act on the movement of avehicle occupant.

[0020] After a hazardous situation, in particular an accident, thehazard-prevention system checks whether the driver is exerting controlover the vehicle and whether a further hazard, for example due to apossible secondary collision, is present. The vehicle is, ifappropriate, placed in a safe state (ignition off, fuel supply off,parking brake on, control of the drive) and an automatic emergency callis emitted. The severity of injuries is estimated by means of the sensedparameters and transmitted to the rescue services.

[0021] In addition to determining the current driver load factor it ispossible to predict an expected driver load factor from the sensed data,which factor is less reliable the longer the prediction time periodwhich is selected. By means of such a prediction it is possible tospecify the time for the issuing of information/warnings to the driverin such a way that the gain in safety is as large as possible. Forexample, an information/warning message is brought forward in order tooutput it in good time before an expected increased loading on thedriver or it is delayed in order to output it only after a driver loadfactor which is increased in the short term. As an alternative or inaddition to this it is possible to select a suitable sense for theinformation/warning, for example it is possible to output an audible,haptic or olfactory warning/information when there is a high degree ofvisual loading on the driver. When there is a high degree of acousticloading, a visual, haptic or olfactory warning/information item cancorrespondingly be issued and/or loading on the driver is reduced byreducing the volume of the radio, for example.

[0022] There are various possible ways of advantageously configuring theteaching of the present invention. One advantageous embodiment of thehazard-prevention system according to the invention will be described inmore detail below with reference to the drawing.

[0023]FIG. 1 shows a schematic block diagram of an advantageousembodiment of the hazard-prevention system according to the invention.An essential component of the hazard-prevention system is the module fordetermining a driver load factor 101 which, in a simple embodiment,divides the severity of the driver load factor into a plurality ofclasses. An example of the division of the classes are the classes: noload factor, low load factor, medium load factor, increased load factor,high load factor and overloading. In a refined embodiment, the driverload factor is categorized by the module 101 and a load class which hasbeen determined is additionally assigned to one or more load categories.Examples of load categories are: acoustic load, visual load, continuousload, load peak and loading by external influences. In order todetermine the specific driver load factor, information is used from themodule 102 for sensing the driving state variables and the surroundings,the module 103 for observing the driver's activity and vehicle occupantsand the module 104 for identifying the driver. The module 102 forsensing the driving state variables and the surroundings, the module 103for observing the driver's activity and vehicle occupants and the module104 for identifying the driver are connected to a memory 105 forrecording features of the driver which characterize the driver, can beused to identify him or permit the state of the driver to be evaluatedby comparing the stored data with current data. Data for characterizingthe driver are, for example, personal strengths and weaknesses,experience, typologies, medical data, sex and age. Data which can beused for identification are, for example, voice, driver type oroperating pattern and position of adjustment devices such asair-conditioning system, pedals, seat adjustment means, steering wheeland joystick. The module 103 for sensing the driver's activity andobserving the vehicle occupants also senses facial expressions, gesturesand physiological data of the driver and the position and the actions ofthe vehicle occupants and these are used in particular to determine theload on the driver. Further parameters which can be determined by themodule 103 and taken into account in the module 101 are driver fatigue,the condition of the driver, the reaction characteristics and thereaction time of the driver, the driving time and the current speedprofile. To a certain extent special sensors are necessary to sensethese parameters. For example, driver fatigue is determined using aviewing direction recognition means, a means for observing the eyesand/or by sensing the steering angle and the actuation of the pedals.Module 102 registers data on the profile of the route so that, forexample, the journey on a routine route is detected by comparison withthe memory 105.

[0024] Data from the memory 105 is additionally used to determine thedriver load factor in module 101. In particular, this data relates tothe characteristics of the driver in similar situations to the situationto be assessed. If data has been stored about the surroundings or theroute profile, it is also taken into account in the determination of thedriver load factor.

[0025] Module 106 has the function, while taking into account theindividual driver load factor, of informing and warning the driver insuch a way that he prevents the hazardous situation. This takes place,for example by virtue of the fact that the driver is relieved by theaudio volume being reduced. Another possible way of adapting the driverwarning is to adapt the warning times to the driver load factor, to thetype of driving and to the perception character of the driver.Furthermore, a sense for informing and warning the driver can beselected as a function of the load factor or of the hazard.

[0026] After the warning/information has been issued, the reaction ofthe driver to the warning/information is assessed in module 107 and theactions of the driver are evaluated to determine whether he hasperceived the information/warning. For this purpose, a viewing directiondetection means may be used which provides a decision basis for whetherthe driver has perceived a warning or an obstacle. As an alternative orin addition it is possible to carry out the evaluation of the driveractions to determine whether they are suitable for preventing the hazardor making possible consequences of an accident less severe. Theevaluation of the actions and reaction of the driver from module 107 istaken into account in the determination of the driver load factor inmodule 101.

[0027] Depending on the result of the evaluation in module 107, module108 brings about a possible intervention into the dynamics of thevehicle movement, causes protection systems to be actuated or/and causesa warning to be issued to other road users. The protection systems whichcan be actuated may act kinematically or dynamically by a restraintsystem being actuated or by a damping element being activated. It ispossible, for example, for a degree of spring stiffness, a materialproperty, a system pressure or the flow characteristics of a fluid to bechanged for this purpose.

1. Hazard-prevention system for a vehicle having: a device for sensingdriving state variables a device for sensing ambient data a device forsensing the driver's activity a data processing device for processingthe sensed data and for actuating a safety device in accordance with apredefined control strategy, characterized in that the vehicle has adevice for identifying the driver, the data processing device derives adriver load factor related specifically to the driver which is derivedfrom the driving state variables, the ambient data and the data relatingto the activity of the driver, the vehicle has a device for adapting thecontrol strategy, which uses the individual driver load factor for thispurpose.
 2. Hazard-prevention system for a vehicle according to claim 1,characterized in that the vehicle has a device for storing thedriver-related history, which contains data which is characteristic ofthe driver, data processing device additionally used as thedriver-related history to derive the individual driver load factor. 3.Hazard-prevention system for a vehicle according to one of claims 1 and2, characterized in that the safety device comprises an information andwarning system.
 4. Hazard-prevention system for a vehicle according toone of claims 1 and 2, characterized in that the safety device comprisesa system for controlling the dynamics of vehicle movement. 5.Hazard-prevention system for a vehicle according to one of claims 1 and2, characterized in that the safety device comprises a vehicle occupantprotection system which acts on the movement of an occupant of a vehicleand is intended to make the consequences of accidents less severe.